YUCAIPA, Calif. – A moderate earthquake shook most of Southern California Thursday, startling people and knocking items off shelves and desks, but there were no immediate reports of significant damage or injuries.
"All of a sudden it just started rocking," said John Napolitano, 45, a campus police officer at Crafton Hills College. "I just sat there and rode it out."
The early afternoon quake had a magnitude of 4.9 and was centered near Yucaipa (search) in San Bernardino County, east of Los Angeles, according to the U.S. Geological Survey (search). About 25 aftershocks followed in a little over an hour, the strongest estimated at magnitude 3.5.
Residents reported shaking from Los Angeles to San Diego and in counties to the east. Rock slides were reported on Highway 38 in the San Bernardino Mountains (search).
"I heard a loud rumbling sound, kind of like thunder," said Nick Brandes, 25, manager of a store in Yucaipa. "At the front, all the customers were in a panic. They were all just in a hurry to get out."
Andrea Cabrera, an employee at the Walgreens drug store in Yucaipa, said the store "just had a few items falling, that's all." Customers "were just stunned, and they just stood there," she said.
The Los Angeles Fire Department received no immediate reports of major damage, spokesman Brian Humphrey said. None of Southern California Edison's 4.6 million customers lost power.
It was the third significant quake to hit California this week: A magnitude-5.2 quake shook Riverside County on Sunday, and a magnitude-7.0 quake struck Tuesday under the ocean 90 miles off Northern California.
Thursday's quake occurred near the San Andreas Fault (search) but not on it, said Lucy Jones, scientist in charge of the U.S. Geological Survey office in Pasadena. She said the quake was not a direct aftershock from Sunday's temblor.
"This is not an unusual level of earthquake activity," Jones said of the state's recent quakes.
Channon Kelly, 31, was eating her lunch in downtown Los Angeles when Thursday's quake hit.
"I almost jumped out of my seat," Kelly said. "I'm starting to get freaked out. We've had so many in the last week, the one Sunday and then in Northern California. I could hear the windows rattling and feel it all at the same time."